Gerding D N, Johnson S, Peterson L R, Mulligan M E, Silva J
Veterans Affairs Lakeside Medical Center, Chicago, Illinois, USA.
Infect Control Hosp Epidemiol. 1995 Aug;16(8):459-77. doi: 10.1086/648363.
To review and summarize the status of diagnosis, epidemiology, infection control, and treatment of Clostridium difficile-associated disease (CDAD).
A case definition of CDAD should include the presence of symptoms (usually diarrhea) and at least one of the following positive tests: endoscopy revealing pseudomembranes, stool cytotoxicity test for toxin B, stool enzyme immunoassay for toxin A or B, or stool culture for C difficile (preferably with confirmation of organism toxicity if a direct stool toxin test is negative or not done). Testing of asymptomatic patients, including those who are asymptomatic after treatment, is not recommended other than for epidemiologic purposes. Lower gastrointestinal endoscopy is the only diagnostic test for pseudomembranous colitis, but it is expensive, invasive, and insensitive (51% to 55%) for the diagnosis of CDAD. Stool culture is the most sensitive laboratory test currently in clinical use, but it is not as specific as the cell cytotoxicity assay.
C difficile is the most frequently identified cause of nosocomial diarrhea. The majority of C difficile infections are acquired nosocomially, and most patients remain asymptomatic following acquisition. Antimicrobial exposure is the greatest risk factor for patients, especially clindamycin, cephalosporins, and penicillins, although virtually every antimicrobial has been implicated. Cases of CDAD unassociated with prior antimicrobial or antineoplastic use are very rare. Hands of personnel, as well as a variety of environmental sites within institutions, have been found to be contaminated with C difficile, which can persist as spores for many months. Contaminated commodes, bathing tubs, and electronic thermometers have been implicated as sources of C difficile. Symptomatic and asymptomatic infected patients are the major reservoirs and sources for environmental contamination. Both genotypic and phenotypic typing systems for C difficile are available and have enhanced epidemiologic investigation greatly.
Successful infection control measures designed to prevent horizontal transmission include the use of gloves in handling body substances and replacement of electronic thermometers with disposable devices. Isolation, cohorting, handwashing, environmental disinfection, and treatment of asymptomatic carriers are recommended practices for which convincing data of efficacy are not available. The most successful control measure directed at reduction in symptomatic disease has been antimicrobial restriction.
Treatment of symptomatic (but not asymptomatic) patients with metronidazole or vancomycin for 10 days is effective; metronidazole may be preferred to reduce risk of vancomycin resistance among other organisms in hospitals. Recurrence of symptoms occurs in 7% to 20% of patients and is due to both relapse and reinfection. Over 90% of first recurrences can be treated successfully in the same manner as initial cases. Combination treatment with vancomycin plus rifampin or the addition orally of the yeast Saccharomyces boulardii to vancomycin or metronidazole treatment has been shown to prevent subsequent diarrhea in patients with recurrent disease.
回顾并总结艰难梭菌相关性疾病（CDAD）的诊断、流行病学、感染控制及治疗现状。
CDAD的病例定义应包括出现症状（通常为腹泻）以及至少一项以下阳性检测结果：内镜检查发现假膜、粪便毒素B细胞毒性试验、粪便毒素A或B酶免疫测定，或艰难梭菌粪便培养（如果直接粪便毒素检测为阴性或未进行，最好确认菌株毒性）。除出于流行病学目的外，不建议对无症状患者进行检测，包括治疗后无症状的患者。下消化道内镜检查是假膜性结肠炎的唯一诊断方法，但它费用高昂、具有侵入性，且对CDAD诊断的敏感性较低（51%至55%）。粪便培养是目前临床使用中最敏感的实验室检测方法，但不如细胞毒性试验特异。
艰难梭菌是医院获得性腹泻最常见的病因。大多数艰难梭菌感染是在医院获得的，大多数患者感染后仍无症状。抗菌药物暴露是患者最大的风险因素，尤其是克林霉素、头孢菌素和青霉素，尽管几乎每种抗菌药物都有相关报道。与先前未使用抗菌药物或抗肿瘤药物无关的CDAD病例非常罕见。已发现医护人员的手以及医疗机构内的各种环境部位被艰难梭菌污染，其可作为孢子持续存在数月。受污染的马桶、浴缸和电子温度计被认为是艰难梭菌的来源。有症状和无症状的感染患者是环境污染的主要储存宿主和来源。目前已有艰难梭菌的基因型和表型分型系统，极大地加强了流行病学调查。
旨在防止水平传播的成功感染控制措施包括在处理体液时使用手套，并用一次性设备替代电子温度计。隔离、分组、洗手、环境消毒以及对无症状携带者进行治疗是推荐的做法，但尚无令人信服的疗效数据。针对减少有症状疾病最成功的控制措施是抗菌药物限制。
用甲硝唑或万古霉素对有症状（而非无症状）患者进行10天治疗有效；甲硝唑可能更受青睐，以降低医院中其他微生物对万古霉素耐药的风险。7%至20%的患者会出现症状复发，这是由复发和再感染导致的。超过90%的首次复发可以采用与初始病例相同的方式成功治疗。已证明万古霉素联合利福平治疗或在万古霉素或甲硝唑治疗中口服添加布拉酵母菌可预防复发性疾病患者随后出现腹泻。
